In the irrigation industry the area to be irrigated is divided into zones. Each zone contains a number of irrigation valves and solenoid valves. Typically, the solenoid valves are opened or closed to deliver more or less water to the different zones in the area being irrigated. One of the systems used to control the operation of solenoid valves, which are located in the various zones to be irrigated, is a decoder system. Typically, in a decoder system a controller sends control signals for opening and closing the irrigation valves through the same electrical wires that supply power to open and close the solenoid operated irrigation valves. An advantage of the decoder system over a conventional controller system is that it reduces the number of electrical wires required in the control system. Also when new irrigation zones are added to the irrigation system it eliminates the need to run additional wires from each of the added irrigation valves to the controller. Instead the wires to control the new irrigation valves can be connected to the nearest decoder or the nearest wires thus avoiding running wires from each of the added valves to the controller. Although the decoder systems eliminate running of multiple wires, the systems are more complex and require multiple wire splices which create a potential for multiple failure points in the system.
Often times the splices in the electrical wire for the decoder systems need to be made to wires that are buried underground since the valves and the wires are located underground. In addition, in the decoder system the splices are usually located in wet locations since the wires are located in the area being irrigated. Therefore care needs to be taken to ensure that the electrical connections are and remain in a waterproof condition.
While there are available direct bury splice kits that allow one to form an electrical connection with a twist-on wire connector numerous splice kits are required for each irrigation system. Using a decoder system, which requires even more electrical wire splices than a conventional system, generally increases the chance that a system failure can occur at one or more of the electrical splices. Commercially available direct bury connectors include splice kits sold by the 3M Company (St. Paul, Minn.) under the name DBY-6 and DBR-6. Typically, such direct bury splice kits have long been used for splicing electrical wires that are to remain underground in dry or wet soils for a length of time. Once an electrical connection is formed in a wire connector, such as a twist-on wire connector, the entire twist-on wire connector is inserted into what is known as a “grease tube”. The grease tube is an elongated test tube like container with an electrically insulating and waterproof material located in the closed end of the tube. The wire connector is forced into the electrically insulating material until the entire twist-on electrical connector is covered with the electrical insulating material. A cover on the end of the tube is then sealed against the exposed portion of wire to retain the twist-on wire connector in the grease tube. The grease tube with the wire connector encapsulated in the electrical insulating material can then be buried underground. In these types of underground systems the twist-on wire connector must be forced endwise into the grease tube by grasping the twisted wire leads that extend from the twist-on wire connector. As the twist-on wire connector is forced to travel endwise into the insulating sealant the electrically insulating sealant must be separated and then allowed to flow back around the twist-on wire connector before the twist-on wire connector and the wire connections therein can be encapsulated. Unless the wire connections are completely covered with insulating material electrical failure can occur after the grease tube is buried underground.